Blasting shots with authority, Juan Martin del Potro could see the finish line as clearly as the baseline when he built a two-set lead. Del Potro was undefeated when holding such an advantage, but the sound of the Argentine's increasingly labored grunts and Roger Federer's fast footsteps provided an audible account of the underdog's dilemma.
Pained by a taped left knee that restricted his movement as the match progressed, del Potro physically faded and Federer lifted his level in rallying for a 3-6, 6-7 (4), 6-2, 6-0, 6-3 triumph to reach his record-tying 31st Grand Slam semifinal.
It was the seventh time the Swiss fought back from a two-set deficit, as Federer showed survival skills against a wounded opponent. Del Potro burst out of the blocks in building a two-set lead, only to feel his aching knee and Federer's improved play conspire against him as the world No. 3 reeled off nine consecutive games in forcing the fifth.
On the strength of some ballistic ball striking and determined court coverage, del Potro broke Federer's serve three times to blitz through the opening set in 40 minutes. In the subsequent set, they traded breaks in the fifth and sixth games, then both saved break points in the eighth and ninth games. The weight and depth of del Potro's fierce, flat strikes forced Federer to defend at times and troubled him on the backhand side.
They went to a tiebreaker, where del Potro took a 4-1 lead with a biting serve down the T. Federer netted a running forehand to face set point. On the 17th shot of the ensuing rally, del Potro pounded a forehand that provoked a Federer backhand into net, as the No. 9 seed seized a two-set lead with a clenched fist.
Signs of del Potro's struggle to push off his left knee were evident as he double faulted to drop serve in the second game of the third set. Federer then saved a break point with a rousing "Allez!" and fired an ace to hold for 4-1. Del Potro held for 2-4, but looked a half-step slow to the ball and did not bother chasing a Federer forehand winner that closed the third set. It took del Potro 59 minutes to win the high-quality second set, but Federer rolled through the third and fourth sets combined in 55 minutes to level the match.
Still, del Potro roused himself for one final push, earning two break points in the opening game of the fifth set. Federer denied both and held with an ace. Federer missed the mark on the down-the-line forehand for stretches of the first set, but he cracked that shot to break at 15 and gain a 3-1 lead in the decider, and never looked back.
Spare a thought for the gifted del Potro, who three years ago dispatched Rafael Nadal and Federer back-to-back to capture the U.S. Open, and appeared poise to make a run at the top spot. But a wrist injury sidelined the big man for much of 2010, and his body betrayed him again today.
Federer is the first man aged 30 or older to reach the French Open semis since Andres Gomez did it en route to winning the 1990 title. He'll face top-ranked Novak Djokovic, who saved four match points in a five-set quarterfinal win of his own, in a rematch of the classic 2011 semifinal.
